First, check all the processes that are running:
SELECT * FROM pg_stat_activity WHERE state = 'active';
So you can identify the PID of the hanging query you want to terminate, run this:
This query might take a while to kill the query, so if you want to kill it the hard way, run this instead:
Need a good GUI Tool for PostgreSQL? TablePlus is a modern, native tool with an elegant UI that allows you to simultaneously manage multiple databases such as MySQL, PostgreSQL, SQLite, Microsoft SQL Server and more.
Not on Mac? Download TablePlus for Windows.
On Linux? Download TablePlus for Linux
Need a quick edit on the go? Download TablePlus for iOS.